The Parenthood and House of Lies stars welcomed their second daughter on Friday, Dec. 19, they announced via Twitter.

“Delta Bell Shepard is here. She doesn’t look like either Kristen or me, but we’re gonna keep her anyway,” Shepard, 39, wrote jokingly.

“The estrogen has now hit critical mass! Good luck, Dax. And welcome to the world DELTA BELL SHEPARD,” Bell, 34, added.

Despite the new addition, not much will change for big sister Lincoln, 21 months. “We were told to pick up the oldest first if both are crying,” the actor told PEOPLE in November.

Shortly after her June announcement that she was expecting, Bell — who showed off her baby belly in a series of stunning ensembles throughout her pregnancy — admitted the couple were stuck on a name for their second child.

“[We’re] completely stumped,” the mom-to-be said in July.

But only two months later, the parents-to-be had a baby name breakthrough. “We’ve settled on one, thankfully,” Bell, who chose to keep their baby’s sex a secret, told PEOPLE in September. “It’s a lot of pressure, especially because we felt Lincoln was so perfect.”

In the days leading up to Delta’s arrival, Shepard shared a video of his wife — whom he wed in 2013 — trying her best to jump start labor.

“Certain members of the family are READY for other members of the family to kindly exit their body,” he captioned a video of Bell bouncing on a ball.